This invention relates to "oral compositions" which term is used herein to designate products which, in the ordinary course of usage, are retained in the oral cavity for a time sufficient to contact substantially all of the dental surfaces but are not intentionally ingested. Such products include, for example, dentifrices, mouthwashes, chewing gums, prophylaxis pastes, non-abrasive gels, topical solutions and the like. This invention more specifically relates to oral compositions which exhibit antimicrobial properties which help to retard the accumulation of dental plaque and/or calculus on the teeth and gums.
Dental plaque is a complex organic film which adheres to and coats the oral hard and soft tissues. The formation and properties of dental plaque are extremely important in the maintenance of oral health since plaque harbors the bacteria which produce dental caries, gingivitis and periodontitis. In fact, dental plaque is composed essentially of bacterial colonies growing in an interbacterial organic matrix that provides adherence of the colonies to the teeth and gingiva and coherence of the colonies to one another. Thus, the elimination or inhibition of dental plaque is related to and beneficial in reducing the incidence of dental caries, gingival inflammation and periodontitis.
As is well known to those skilled in the art, dental caries is caused principally by dissolution of tooth mineral by biologically produced intra-oral acids. Such biologically produced intra-oral acids primarily are produced by some of the bacterial colonies that constitute dental plaque. Gingival inflammation, which is the first stage of the more severe periodontitis, is produced by the inflammatory products of bacterial plaque metabolism. Among these bacterial metabolites one can mention hydrolytic enzymes, endotoxins and antigens. Thus, the elimination of the medium which comprises such caries and gingivitis producing bacteria is believed to directly affect the incidence of dental caries and periodontitis.
The formation of dental plaque is not fully understood but it is known to result from the growth and colonization of various strains of oral bacteria on the surface of the teeth and gingiva. Further, there is believed to be a direct relationship between the ability of dental plaque to induce the precipitation (crystallization) of calcium salts on the surface of the teeth and formation of dental calculus.
Dental calculus is a hard deposit found on the surfaces of the teeth which results from the precipitation of calcium salts in an organic matrix, primarily plaque. Thus, calculus can be defined as calcified plaque. Calculus is related to dental health since its presence is associated with pathological changes in the bone, gingiva and other supporting periodontal structures. Thus, the elimination and retardation of the formation of dental plaque is an important factor in dental hygienic and health programs not only in the reduction of dental caries and periodontal disease but also the reduction of the formation of dental calculus.
The utilization of antibacterial or antimicrobial agents such as antiseptics and germicides for topical application in the oral cavity is well known in the art. By way of explanation, an antiseptic ordinarily is considered to be an agent which stops or inhibits the growth of microorganisms without necessarily killing them. In contrast, a bacteriocide or germicide is any substance which kills or destroys bacteria. Frequently, the difference between bacteriostatic and bacteriocidal effects is a quantitive function of the concentration of the antibacterial agents or a qualitative function of the agent itself.
Less irritating antiseptics find wide usage for topical application on the oral mucosa for the control of minor infections and on dried mucosa in preparation for needle insertion. Antiseptics too irritating for use on soft tissue find application within the tooth structure for root canal sterilization or cavity medication. Germicides have also been incorporated in commercial mouthwashes which are medicated liquids used for cleaning the mouth or treating disease states in the oral mucous membrane.
The use of such antiseptic agents has many times resulted in severe staining problems with the teeth which would mitigate against their use even if they were effective against plaque.